Combine the herbs and spices for the Cajun seasoning and set aside.
Peel and dice the potatoes into ½-inch cubes. Place the cubed potatoes in a large pot, sprinkle 1 tsp salt over top, then cover with water.
Place a lid on the pot and bring it up to a boil over medium-high heat. Once boiling, reduce the heat slightly and continue to boil the potatoes until they are very tender (about 8 minutes, test with a fork). Drain the potatoes in a colander and rinse briefly with cool water.
While the potatoes are boiling, prepare the potato salad dressing so the flavors have some time to blend. In a bowl, stir together the mayonnaise, mustard, red wine vinegar, hot sauce, sugar, and the prepared Cajun seasoning. Set the dressing aside.
Chop the hard boiled eggs, finely dice the celery, slice the green onions, and chop the parsley.
Once the potatoes are mostly cooled, transfer them to a large bowl with the eggs, celery, green onion, and parsley. Pour the dressing over top, then stir until everything is well combined. Give the potato salad a taste and adjust the salt or other seasonings to your liking. Serve warm or chill until ready to eat.
*In place of the homemade Cajun seasoning, you can use about 1 Tbsp store-bought Cajun seasoning. Make sure to check if the seasoning contains salt and if it doesn't, you'll need to add salt to the potato salad dressing.